[PATCH] D39829: add new check for property declaration

[Ben Hamilton via Phabricator via cfe-commits]

benhamilton added inline comments.


================
Comment at: clang-tidy/objc/PropertyDeclarationCheck.cpp:41
+      objcPropertyDecl(
+          // the property name should be in Lower Camel Case like
+          // 'lowerCamelCase'
----------------
There are some exceptions we should special case. Acronyms like `URL` and `HTTP` and `HTML` are allowed at the beginning of method names (and property names—although that is not explicitly mentioned, property names follow the same guidelines as method names):

https://developer.apple.com/library/content/documentation/Cocoa/Conceptual/CodingGuidelines/Articles/NamingBasics.html#//apple_ref/doc/uid/20001281-1002931-BBCFHEAB

> For method names, start with a lowercase letter and capitalize the first letter of embedded words. Don’t use prefixes.
> `fileExistsAtPath:isDirectory:`
>
> An exception to this guideline is method names that start with a well-known acronym, for example, `TIFFRepresentation` (NSImage).

There is a list of well-known acronyms listed here:

https://developer.apple.com/library/content/documentation/Cocoa/Conceptual/CodingGuidelines/Articles/APIAbbreviations.html#//apple_ref/doc/uid/20001285-BCIHCGAE

```
ASCII
PDF
XML
HTML
URL
RTF
HTTP
TIFF
JPG
PNG
GIF
LZW
ROM
RGB
CMYK
MIDI
FTP
```



================
Comment at: docs/clang-tidy/checks/google-objc-global-variable-declaration.rst:1
 .. title:: clang-tidy - google-objc-global-variable-declaration
 
----------------
Let's remove "google-" everywhere and mention only Apple's style guide.


================
Comment at: docs/clang-tidy/checks/objc-property-declaration.rst:7
+Finds property declarations in Objective-C files that do not follow the pattern
+of property names in Google's Objective-C Style Guide. The property name should
+be in the format of Lower Camel Case.
----------------
hokein wrote:
> benhamilton wrote:
> > hokein wrote:
> > > Google style? but the link you provided is Apple.
> > Google's Objective-C style guide is a list of additions on top of Apple's Objective-C style guide.
> > 
> > Property naming standards are defined in Apple's style guide, and not changed by Google's.
> I see, thanks for the clarification, I think the "Apple" would be clearer.
Yeah, we don't want to mention Google here. Apple is good.


================
Comment at: test/clang-tidy/objc-property-declaration.m:8
+ at property(assign, nonatomic) int camelCase;
+// CHECK-MESSAGES-NOT: :[[@LINE-1]]:34: warning: property 'camelCase' is not in proper format according to property naming convention [objc-property-declaration]
+ at end
----------------
Wizard wrote:
> hokein wrote:
> > Why does the check catch this case? Isn't `camelCase` a correct name?
> This is CHECK-MESSAGES-NOT
I think in that case you don't need an explicit CHECK (there is implicitly a "CHECK-MESSAGES-NOT" on every line for all warnings which fails the test if a warning is raised).


https://reviews.llvm.org/D39829